629 research outputs found

    The Shadow Economy and Morals: A Note

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    If the established rules are obeyed spontaneously in an economy, this increases economic efficiency since the uncertainties, monitoring costs and incentive problems induced by opportunism can be avoided. Opportunism will be increasedby increasing the incentives for unlawful behaviour, however, and a slight increase in these incentives might cause a cumulative and self-nourishing breakdown of morals. The dangers of the growing shadow economy are louring here

    Operations Research Methods for Multi-Domain Campaign Phase Planning

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    In Antiaccess Warfare as Strategy, Tangredi posits the question and need to consider multiple domains and governmental and warfighting functions in various phases of campaign execution. Multi-domain integration within and across various phases of the joint campaign presents a host of non-linear factors that are compounded and amplified by uncertainties. Colonel Blotto is a simple game that is suited to compare traditional force-on-force military engagements where mass wins the day, but have had limited application to more complex military planning. This thesis explores the formulation schema, data-driven parameters, methods of calculation, and scenarios applicable to a generalized Colonel Blotto (General Blotto) game. It explores this generalized game theory framework, its applicability to multi-domain operations, and recommends future research areas that could help to extend its applicability, enabling planners and commanders to gain similar insight as to those straight-forward applications

    Explaining Africa’s public consumption procyclicality : revisiting old evidence

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    This paper compiles a novel dataset of time-varying measures of government consumption cyclicality for a panel of 46 African economies between 1960 and 2014. Government consumption has, generally, been highly procyclical over time in this group of countries. However, sample averages hide serious heterogeneity across countries with the majority of them showing procyclical behavior despite some positive signs of graduation from the “procyclicality trap” in a few cases. By means of weighted least squares regressions, we find that more developed African economies tend to have a smaller degree of government consumption procyclicality. Countries with higher social fragmentation and those are more reliant on foreign aid inflows tend to have a more procyclical government consumption policy. Better governance promotes counter- cyclical fiscal policy whileincreased democracy dampens it. Finally, some fiscal rules are important in curbing the procyclical behavior of government consumption.info:eu-repo/semantics/publishedVersio

    Arbeitsmarkt und BeschÀftigung

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    The Labor Market and Employment (Handbook article). The labor market differs from typical markets in important ways. We find job competition and collective mechanisms that set wages and working conditions. Changes in employment bring about changes in wages and prices and entail political and monetary responses. The goals of price stability and full employment cannot, usually, be attained simultaneously under the present conditions.Der Arbeitsmarkt unterscheidet sich grundlegend von anderen MĂ€rkten. Wir finden hier einen ausgeprĂ€gten Qualifikationswettbewerb und kollektive Mechanismen der Festlegung von Entlohnungs- und Arbeitsbedingungen. BeschĂ€ftigungsĂ€nderungen mĂŒssen im Zusammenhang mit Lohn- und Preisbewegungen gesehen werden. Die wirtschaftspolitischen Ziele von VollbeschĂ€ftigung und PreisstabilitĂ€t stehen bei den gegebenen Lohnsetzungsmechanismen typischerweise im Widerspruch zueinander

    In Vitro Characterisation of Physiological and Maximum Elastic Modulus of Ascending Thoracic Aortic Aneurysms Using Uniaxial Tensile Testing

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    AbstractObjectiveAscending thoracic aortic aneurysms (ATAA) are a life-threatening condition due to the risk of rupture or dissection. This risk is increased in the presence of a bicuspid aortic valve (BAV). The purpose of this study was to provide data on the elastic modulus of aortic wall of ATAA using uniaxial tensile testing in two different areas of the stress–strain relationship: physiological and maximum range of stresses. The influence of tissue location, tissue orientation and valve type on these parameters was investigated.Materials and methodsTissues freshly excised from ATAA with bicuspid or tricuspid aortic valve were obtained from greater and lesser curvature (GC and LC) and the specimens were tested uniaxially in circumferential (CIRC) and longitudinal (LONG) orientation. Maximum elastic modulus (MEM) was given by the maximum slope of the stress–strain curve before failure. Physiological modulus (PM) was derived from the Laplace law and from ranges of pressure of 80–120 mmHg. Means of each group of specimen were compared using Student's t-test to assess the influence of location, orientation and valve type on each mechanical parameter.ResultsPM was found to be significantly lower than the MEM (p < 0.001). The MEM and PM were significantly higher (p < 0.01) in the CIRC (n = 66) than in the LONG orientation (n = 42). The MEM was higher in the circumferential orientation in the BAV group (p < 0.001 in GC and p < 0.05 in LC). MEM and PM in GC specimens were higher in the longitudinal orientation than the LC specimens (p < 0.05).ConclusionThis study demonstrates the anisotropy of the aortic wall in ATAA and provides data on the mechanical behaviour in the physiological range of pressure

    How often does the Unruh-DeWitt detector click? Regularisation by a spatial profile

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    We analyse within first-order perturbation theory the instantaneous transition rate of an accelerated Unruh-DeWitt particle detector whose coupling to a massless scalar field on four-dimensional Minkowski space is regularised by a spatial profile. For the Lorentzian profile introduced by Schlicht, the zero size limit is computed explicitly and expressed as a manifestly finite integral formula that no longer involves regulators or limits. The same transition rate is obtained for an arbitrary profile of compact support under a modified definition of spatial smearing. Consequences for the asymptotic behaviour of the transition rate are discussed. A number of stationary and nonstationary trajectories are analysed, recovering in particular the Planckian spectrum for uniform acceleration.Comment: 30 pages, 1 figure. v3: Added references and minor clarification

    Is life a thermal horizon ?

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    This talk aims at questioning the vanishing of Unruh temperature for an inertial observer in Minkovski spacetime with finite lifetime, arguing that in the non eternal case the existence of a causal horizon is not linked to the non-vanishing of the acceleration. This is illustrated by a previous result, the diamonds temperature, that adapts the algebraic approach of Unruh effect to the finite case.Comment: Proceedings of the conference DICE 2006, Piombino september 200

    Transition rate of the Unruh-DeWitt detector in curved spacetime

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    We examine the Unruh-DeWitt particle detector coupled to a scalar field in an arbitrary Hadamard state in four-dimensional curved spacetime. Using smooth switching functions to turn on and off the interaction, we obtain a regulator-free integral formula for the total excitation probability, and we show that an instantaneous transition rate can be recovered in a suitable limit. Previous results in Minkowski space are recovered as a special case. As applications, we consider an inertial detector in the Rindler vacuum and a detector at rest in a static Newtonian gravitational field. Gravitational corrections to decay rates in atomic physics laboratory experiments on the surface of the Earth are estimated to be suppressed by 42 orders of magnitude.Comment: 27 pages, 1 figure. v3: Typos corrected. Published versio

    Selection Wages and Discrimination

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    Applicants for any given job are more or less suited to fill it, and the firm will select the best among them. Increasing the wage offer attracts more applicants and makes it possible to raise the hiring standard and improve the productivity of the staff. Wages that optimize on the trade-off between the wage level and the productivity of the workforce are known as selection wages. As men react more strongly to wage differentials than females, the trade-off is more pronounced for men and a profit-maximizing firm will offer a higher wage for men than for women in equilibrium

    Accelerated detectors in Dirac vacuum: the effects of horizon fluctuations

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    We consider an Unruh-DeWitt detector interacting with a massless Dirac field. Assuming that the detector is moving along an hyperbolic trajectory, we modeled the effects of fluctuations in the event horizon using a Dirac equation with random coefficients. First, we develop the perturbation theory for the fermionic field in a random media. Further we evaluate corrections due to the randomness in the response function associated to different model detectors.Comment: 19 pages, 1 figur
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